Use FrameAllocator rather than Heap for shared memory pool. am: f171294ea5

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Virtualization/+/23153906

Change-Id: I03306eba5d1ffbac128546bc0f777c197811081a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>